CSF p‐NfH and NfL levels were significantly increased in ALS patients (3.107 ng/mL and 4333.6 pg/mL, respectively) compared with HC (0.223 ng/mL, P < .0001, and 272.5 pg/mL, P < .0001), DC (0.917 ng/mL and 1908.2 pg/mL, P < .0001) and SMA type 3 patients (0.164 ng/mL, P < .0001, and 259.7 pg/mL, P < .0001) (Figure 1A, B). Here, NEFL is linked to amyotrophic lateral sclerosis.